feature: Enable client certificate rotation by using tls.Config@GetClientCertificate

[benkelukas]

Enable client certificate rotation by providing a callback to tls.Config@GetClientCertificate when setting up Temporal connection

Reason for This PR

Closes: #522

Description of Changes

Added a callback for GetClientCertificate to enable client certificate rotation when mTLS connection fails, e.g. after it changes in the referenced cert and key files

License Acceptance

By submitting this pull request, I confirm that my contribution is made under
the terms of the MIT license.

PR Checklist

[Author TODO: Meet these criteria.]
[Reviewer TODO: Verify that these criteria are met. Request changes if not]

• All commits in this PR are signed (git commit -s).
• The reason for this PR is clearly provided (issue no. or explanation).
• The description of changes is clear and encompassing.
• Any required documentation changes (code and docs) are included in this PR.
• Any user-facing changes are mentioned in CHANGELOG.md.
• All added/changed functionality is tested.

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All committers have signed the CLA.

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 36.49%. Comparing base (c8e0bcf) to head (4b385c2).
Report is 213 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #523       +/-   ##
===========================================
+ Coverage   22.67%   36.49%   +13.81%     
===========================================
  Files           4       13        +9     
  Lines         269      959      +690     
===========================================
+ Hits           61      350      +289     
- Misses        206      539      +333     
- Partials        2       70       +68     

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[rustatian]

Thanks, @benkelukas 👍 LGTM, will be released next week with RR v2024.1.3.

[benkelukas]

Thanks @rustatian - that's great news! 🎉